Numerous attempts have been made in the field of veterinary medicine to measure the forces and timing of forces applied to the foot of a quadruped, and more particularly horses. This type of information is not only helpful for determining the stress applied to a foot, but may also be used as a diagnostic tool to analyze gait, stride, lameness and other symptoms which occur as a result of an animal's natural motion. Furthermore, this data is especially useful for analyzing racehorses, which are susceptible to injury and which may develop undesirable ambulatory mechanics if afflicted by foot and leg injuries which are undetected and untreated.
One type of apparatus used to measure forces exerted against the foot of a quadruped involves the positioning of a pressure plate, or platform, on the ground surface. The animal is then directed to walk or run over the surface and the force exerted by the foot of the animal is measured. However, these types of platforms are generally heavy, difficult to transport and are constructed of a hard surface which is generally avoided by a moving horse. Furthermore, these apparatus are only capable of measuring the total magnitude of force exerted against an entire foot surface, and not measure a distribution of forces applied against different portions of the foot.
Other apparatus have been developed which are worn on the foot of a quadruped, and thus avoid the transportation problems associated with the platforms previously mentioned. These devices include the use of accelerometers, resistive load cells, or force sensors with piezo transducers to measure the force applied against the foot of an animal. However, each of these devices only measures the total force exerted against the foot of an animal, and not the distribution or timing of those forces. More particularly, these devices have only been used to measure the force exerted against the rigid hoof of a quadruped, and not the force exerting against the remainder of the foot surface. Further, these devices have not been found to be durable and are difficult to calibrate as a result of the extreme pressures exerted by a horse or other large animal while running or jumping.
Finally, motion picture cameras and sound recording devices have been used to identify the timing of a quadruped's hoofs touching the ground. This information is then compiled and analyzed to measure gait and other ambulatory functions, but is limited in that it does not provide any information indicative of the force or distribution of forces applied against the foot of the animal. Additionally, these types of devices are burdensome, require a significant investment in expensive, cumbersome equipment, and generally cannot be utilized around an entire track or lengthy racing surface.
Thus, for the aforementioned reasons a significant need exists in the art for an apparatus and method for continuously measuring the distribution of forces applied against the foot of a quadruped. The device must be lightweight, capable of being worn by the animal without altering its natural movement, and durable enough to withstand the extreme foot pressures associated with large animals. Further, the device must be capable of measuring not only the distribution of forces against a hoof, or entire foot, but must be able to measure the timing of forces to process data indicative of gait, lameness and stride of the animal. Finally, it would be advantageous if the device would facilitate the processing and feedback of data indicative of force and ambulatory functions at a remote location. This capability would allow a trainer or rider of the quadruped to instantaneously evaluate data and respond accordingly for optimum ambulatory efficiency.